In the field of underground or open-work mining as well as in road or structural engineering, several milling systems are known for the milling of rock and other hard materials such as extraction products, tarmac, and concrete components. For such milling operations, rotary driven drums or discs including milling tools mounted at the circumference thereof in an evenly distributed manner are mainly used. As an example, round shaft bits may be used as milling tools. During the milling operation, milling tools successively wear until they have to be replaced. Wear of milling tools is even increased in milling of hard materials.
Due to costly replacements of worn cutting tools, extending the service life of milling tools is subject of ongoing interest for milling system manufactures.
One approach in reducing the wear rate of milling systems aims on reducing the cutting time of each individual milling tool. For example, by providing a plurality of individual milling tools, each being in milling operation for only a short time span, the wear rate of each milling tool may be reduced as heat peaks which considerably increase wear may be reduced.
As an example, WO 2006/079536 A1 discloses a device for milling treatment. The device includes a spindle drum which is rotatably mounted on a drum support and rotatable about a drum axis. In the spindle drum, several tool spindles are supported eccentrically to the drum axis to be rotatably driveable about spindle axes. Each tool spindle carries a machining tool at its end projecting from the spindle drum.
As a further example, DE 288 984 C discloses a shearer including two rotatable discs. On both sides of each disc, a plurality of cutting cylinders is provided.
The present disclosure is directed, at least in part, to improving or overcoming one or more aspects of prior systems.